/**
 * Software License, Version 1.0
 * 
 * Copyright 2003 The Trustees of Indiana University.  All rights reserved.
 * 
 *
 *Redistribution and use in source and binary forms, with or without 
 *modification, are permitted provided that the following conditions are met:
 *
 *1) All redistributions of source code must retain the above copyright notice,
 * the list of authors in the original source code, this list of conditions and
 * the disclaimer listed in this license;
 *2) All redistributions in binary form must reproduce the above copyright 
 * notice, this list of conditions and the disclaimer listed in this license in
 * the documentation and/or other materials provided with the distribution;
 *3) Any documentation included with all redistributions must include the 
 * following acknowledgement:
 *
 *"This product includes software developed by the Community Grids Lab. For 
 * further information contact the Community Grids Lab at 
 * http://communitygrids.iu.edu/."
 *
 * Alternatively, this acknowledgement may appear in the software itself, and 
 * wherever such third-party acknowledgments normally appear.
 * 
 *4) The name Indiana University or Community Grids Lab or NaradaBrokering, 
 * shall not be used to endorse or promote products derived from this software 
 * without prior written permission from Indiana University.  For written 
 * permission, please contact the Advanced Research and Technology Institute 
 * ("ARTI") at 351 West 10th Street, Indianapolis, Indiana 46202.
 *5) Products derived from this software may not be called NaradaBrokering, 
 * nor may Indiana University or Community Grids Lab or NaradaBrokering appear
 * in their name, without prior written permission of ARTI.
 * 
 *
 * Indiana University provides no reassurances that the source code provided 
 * does not infringe the patent or any other intellectual property rights of 
 * any other entity.  Indiana University disclaims any liability to any 
 * recipient for claims brought by any other entity based on infringement of 
 * intellectual property rights or otherwise.  
 *
 *LICENSEE UNDERSTANDS THAT SOFTWARE IS PROVIDED "AS IS" FOR WHICH NO 
 *WARRANTIES AS TO CAPABILITIES OR ACCURACY ARE MADE. INDIANA UNIVERSITY GIVES
 *NO WARRANTIES AND MAKES NO REPRESENTATION THAT SOFTWARE IS FREE OF 
 *INFRINGEMENT OF THIRD PARTY PATENT, COPYRIGHT, OR OTHER PROPRIETARY RIGHTS. 
 *INDIANA UNIVERSITY MAKES NO WARRANTIES THAT SOFTWARE IS FREE FROM "BUGS", 
 *"VIRUSES", "TROJAN HORSES", "TRAP DOORS", "WORMS", OR OTHER HARMFUL CODE.  
 *LICENSEE ASSUMES THE ENTIRE RISK AS TO THE PERFORMANCE OF SOFTWARE AND/OR 
 *ASSOCIATED MATERIALS, AND TO THE PERFORMANCE AND VALIDITY OF INFORMATION 
 *GENERATED USING SOFTWARE.
 */
/*
 * Topology Viewer
 */

package cgl.narada.topology.viewer;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * Represents a subscription request (to a broker) by a client
 */
public class Subscription {
    int clientId;
    String clientType;
    List topics;

    /**
     * Only constructor
     */ 
    public Subscription(int clientId, String clientType) {
	this.clientId = clientId;
	this.clientType = clientType;
	topics = new ArrayList();
    }

    /**
     * Adds a topic into the list associated with a client's subscription
     * @param t <code>String</code> representation of a topic.
     */
    public void addTopic(String t) {
	if (getTopic(t) == null) {
	    topics.add(t);
	} else {
	    //topic present in the list
	}
    }

    /**
     * Deletes the specified topic from the list associated with a client's
     * subscription.
     * @param t <code>String</code> representation of a topic.
     * @throws TopologyException if the specified topic does not exist
     */
    public void deleteTopic(String t) throws TopologyException {
	String topic = getTopic(t);
	if (t == null) {
	    throw new TopologyException("topic not present while deletion");
	} else {
	    topics.remove(topic);
	}
    }

    /**
     * Deletes all the topics associated with client's subscription.
     */
    public void deleteAllTopics() {
	Iterator it = topics.iterator();
	while (it.hasNext()) {
	    it.remove();
	}
    }
    
    /**
     * Fetches a topic from the topic list assiciated with the client's 
     * subscription.
     * @param  t <code>String</code> representation of the topic to be fetched.
     * @return <code>String</code> representation of the topic. 
     *         <code>null</code> if the specified topic is not found.
     */
    public String getTopic(String t) {
	Iterator it = topics.iterator();
	while (it.hasNext()) {
	    String topic = (String) it.next();
	    if (topic.equals(t)) {
		return topic;
	    }
	}
	return null;
    }
};
